Improvement in the manufacture of iron and steel



Unrinn STATES PATENT @arielal JOHN MIDDLETON, OF PHILADELPHIA, PENNSYLVANA.

IMPROVEMENT IN THE MANUFACTURE OF IRON AND STEEL.

Specification forming part of Letters Patent No. 112,828, dated March 21, 1871.

I, JOHN W. MiDDLEToN, of the city of Philadelphia, in the State of Pennsylvania, have invented certain further `Improvements in the Process of Manufacturing Iron and Steel direct from the ore, and the apparatus therefor, of which the following is a specification:

N atugrc and Objects of the Intention.

The rst part of my invention relates to the combined arrangement of a deep Crucible or hearthf having a vertical series of tuyere or Y blast holes through its sides, and adjustable nace, and forthe further purification and rening of the same by a oneeheat process acting Continuously from the said reducing-furnace to the usual attening or vstraightening plate, on which the finished article is left to Cool.

The second part of my invention relates to the Construction of the interior of an ore-rcducing furnace with a contraction so made as to form a burden-supporting projection around in the inner side of the stack, in combination with a spherical chamber between the said projection and the Crucible; the object of this part of my invention being to diminish the pressure of the burden upon the pasty or partially-melted metal, which is supported by the boshes, and to afford or allow a more general and effective action of the blast in liquefying the metal and slag before they enter the cru-k Cible or hearth, and also to prevent the usual wedging action of the burden upon the pasty mass, whereby the blast is liable to be sluit off.

Thethird part of my invention relates to the employment of a hot-blast` channel, flue, or chamber around and under the crucible or hearth of an ore-reducing furnace, the said Channel, flue, or chamber being constructed in such a manner that a blast of waste heat or gas, or the heat of special fire, or of the usual blast on its way to the said reducing-furnace, will pass into and through the said channel, or around and underfthe Crucible or hearth, and keep the latter, at lall times during the operation ofthe furnace, in a strongly-heated Condition the object of this part of myinvention being twofold-irst, to prevent the possibility of the melted iron and yslag in the said crucible or hearth from becoming Chilled;7 and, second, to keep the contents of the said Crucible at all times in the most iiuid condition possible, and therefore in the most advantageous state for the separation of the iron and slag therein, by gravitation, preparatory to casting in flasks or molds, or to the further refinement or dec'arburization of the iron without cooling or the loss of its heat. y

The fourth part of my invention relates to the construction and relative arrangement of the heat-generating furnace, the ore-reducin g furnace, and the intervening chambers, for separating the iron and slag by gravit-ation in a refining-vessel, purifying, ldecarburizing, working, or kneadingl automatically the iron, and thus producing malleable iron or steel, so that in driving the hot blast Continuously through from the heat-generating furnace to the ore-reducing furnace the ,portion of the blast which may from time to time be required in the purifying, decarburizing, and puddling or kneading Chamber shall pass, with the exhalations or impurities derived, in a different direction, or so as not to re-enter the reducin g-furnace, but may be used for heating blast, generating steam, and calciningore 5 the object of this part of my invention being to use the blast for both reducing and reflnin g without returning the expelled impurities into the reducing-furnace.

The fifth part of my invention relates to the combination, with the hotblast of an ore-rcducing furnace, of a special heat-generating furnace, in such a manner as to enable the workmen to readily superheat or intensify the heat of the said hot-blast on its; passage A. through the special furnace to any degree re- -f quired; the object of this part of my invention being to enable the workmen to melt out either Cast or malleable iron when the same has become chilled in the said ore-reducing furnace, thus avoiding the great expenditure of time, labor, and money heretofore required in clearin g out the said chilled or consolidated mass.

The sixth part of my invention relates to the combination, with the hot-blast ore-reducing, of a special blast-superheating furnace in a Close channel, communicating directly with the said ore-reducing furnace, and containing a vessel for refining by gravitation; the object of this part of my invention being to pro! duce refined cast-iron, or malleable iron and steel, in a condition to be formed into ingots and bars, direct from the ore by and during a single or continuous heat.

Description of the Accompanying Drawing.

cally. Fig. 4 is a perspective view, showing the interior of said refining and decarburizing chamber detached, and its pipes or tuyeres opening in slanting directions into its pool. Fig. 5 is a horizontal section, showing the lower portion of one of the ingot-molds as closed. Fig. 6 is a vertical section, showing one-half of the mold as divided in a vertical plane between two diagonally-opposite Cones ofthe same. Fig. 7 is a representation ot` the four parts of the said mold opened.

General Description.

The Crucible A 'is a deep cylindrical chamber, extending vertically downward from the boshes a", and provided with a vertical series of tuyere or blast holes, a a. Around and beneath the Crucible A the chamber, i'lue, or channel B is constructed, and arranged so that aportion of thehot-blast from the heatgeneratin g furnace C will enter or pass through lthe same, and thus keep the walls and bottom of thesaid Crucible or hearth highly heated.

The blast from' the heat-generating furnace C enters the run-out at the bottom of the Crucible A, as connected in the drawing; but, with the ordinary blast-furnace blast and this improved purifyin g-crucible and heated Chamber, as the melted metal rises in the Crucible the opening is to be stopped, and the blast introduced through the hole to be then opened next above, and so on, in succession, with all the holes until the Crucible is filled with the melted iron and slag. The said external blast is introduced thro ugh the several tuyere-h oles, each of which is provided with a pipe, a, which `passes throughI the surrounding hot channel or chamber B. All the said holesiare, of course, to be kept stopped, except those vthrough which the blast is driven.

spherical`chamber a below will be suffi-v cientl y relieved to allow the blast to penetrate it, and thus more rapidly reduce the same to the uid -state for running into the crucible A below, and at the same time permit a more diffused action of the blast upon the pasty mass, and thus avoid that narrow, concentrated, and consequently intensely hot and cutting action 'of the blast, which reduces the calcium, silicon, or other metallic elements which are contained in most of the ores and fluxes, and render the iron impure or unsuit able for some purposes.

The heat-generating furnace C has a large fuel-magazine, c', with airtght fittings, so constructed and applied as to hold the days supply, or more, ofthe fuel, and feed itto the blast by gravitation, as the combustion of the.

fuel may require, and at 'the same time prevent the ingress and egress of air through the magazine.

The fuel rests upon a grate if cold-blast he used for its combustion, or on the bottom of the furnace if l1ot-blast be used; and the blast is drivenI intoit at this point so as to produce a rapid combustion, and drive a 'steady and powerful current of the intensely-heated products ot' combustion upward and onward through the passage-way D and the Crucible A of the ore-reducing furnace.

A fluxin g substance may be used with the fuel, if necessary, and the slag let out through a tap-hole in the bottom of rthe furnace C.

The refining,puddling, and automaticallykneadin g chamber E is arranged at one side of the direct-draft chambers D D, and communicates therewith through an opening, e',

which is fitted with a sliding door, so that.

when this chamber E is not in use, or needs repairs, or any temporary cessation of its. operation, the same can be closed, and the blast thus prevented from entering. rlhe object in putting this cli amber aside from the line of the direct draft is to use a sutiicient portion ofthe latter for refining, paddling, &c.,without send ing the impurities separated inthe said chamber E back again into the ore-reducing furnace--a result which would necessarily follow it' the said purifying-Chamber were` placed in the direct line of the blast from the heat-gemeint ing chamber to the ore-reducing furnace.

The general structure of the chamber E, with its tuyere-pipes e' c', pool e", and the apparatus for causing air or gas to be driven through the said tuyerepipes in short, rapid, air-gun-like shots, which will knead the contents of the pool automatically, `having been described in a prior application, (D,) now before the Patent Office, a further description need not be here made, except to say that ,we ach of the series of said tubes is intended to make a shot per second of time, and in such succession as tokeep the whole contents of the. pool in'rapid and thorough agitation.

The vessel d in the chamber D, for more perfectly separating the slag and iron by gravitation, having been described in a prior application, (B,) need not be further described here.

The ingot-molds (see Figs. 5, 6, 7) are made in long sections F F F F, which can be readily adjusted and held together by a slip-band or otherwise, so as to afford an upright ingotmold with a long slender throat, f', whereby a head-pressure can be given to the melted contents poured into the mold through the mouth and neck, and thus the ingot be more effectually condensed, and so, also, that when the metal has set the mold can be quickly opened, the ingot cut from the stem, and then taken out and elongated between the usual rolls or under the hammer without reheatin g.

By the use of a core, j",two, three, or more ingots may be cast in a mold having but the one mouth and throat j", and the same condensin g result produced by head-pressure.

Between the heat-generating furnace C and the ore-reducing furnace numerous air-tight doors, and iiues with well-secured dampers and valves, as may best suit convenience, must be arranged, for access to and inspection of the different chambers.

Two or more of the refining-chambers E may be connected with the direct-blast chamber D in the same manner as indicated by the dotted lilies V in Fig. 4.

To sum up brieiy, 1 will say that, by means of the processes and apparatus described in my previous applications, (A, B, C, D,) in connection with the improvements herein described, castings, steel, and malleable iron can be produced from the ore with more economy of fuel, (itbein g a single-heat process,) with less labor, and in less time, and better qualities in the metal produced frolnthe same kind of materials than any other hitherto-known mode.

Commencing with the tunnel-head of the ore-reducing furnace herein described, either with or without the heating-due aroumland under the crucible, or, beginning with the liquid scoria and iron, from any ore-reducing, one or more ofthe portable gravitation-vessels described in application A will enable the operator to obtain a better article of iron, direct from the furnace, for pouring into molds or flasks for casting; or, commencing with the liquid iron and slag as made by a continuous stream or periodically from any furnace, the fiuid running through the passage to the iron and slag pool, a large portion of the slag can be drawn oft', if desired. Then tap the iron and slag into the vertical gravitation-vessel in the hot chamber below, wherein may be placed chemicals in a box to be opened by a torpedo, as described in application D, and the iron thus purified and poured into molds, producing first-class castings.

For steel or malleable iron, continue the process from the gravity-vessel, the liquid iron, which can be entirely ,freed from slag and many impurities, running along its gutter into finery, boiling, puddling, or as automatically kneaded byl means of the apparatus describedy in application D, whereby numerous air-gunlike shots of air, superheated steam, or hot- The blast driven into the iron in the pool. said shots are intended to belet off and continued from each tuyere-pipe about every second of time, and each shot made consuming one-tenth to five-tenths of a second, thereby more thoroughly working out most of the impurities and decarburizing it for steel, or continuing it for malleable iron without the use of the squeezers,7 then casting the liquid malleable iron or steel into molds placed in a hot chamber for gravityAcondensed ingots, as described herein, and when sufficiently set rolled into bars of any sizes desired.

If preferred, iu'place of casting intoin gots, the liquid iron or steel canbe sufficiently cooled in the furnace where decarburizcd, and then made into balls and shaped into blooms by.

the squeezers, and finally rolled or hammered into bars and laid upon the straightening plate to cool.

Claims.

I claim as my invention- 1. 'lhe combination, with a hot-blast ore-reducing furnace, of the deep Crucible A, the adjustable tuyere-pipes c c, and the vertical series of tuyere-holes c c', the said parts being constructed and arranged substantially as described, for the purpose of more effectually causing the separation of the metal and slag in the crucible, and allowing the tuyereholes in the latter to be successively closed with facility, as the melted metal and slag rise in the said crucible, until the same be full.

2. In an ore-reducing furnace, the annular shoulder or contraction c4 a5, in combination f with the spherical chamber a" and the cruci ble A, substantially as and for the purpose hereinbefore described and set forth.

3. The hotblast chamber, channel, or flue B around and under the'crucible A, substantially as and for the purpose hereinbefore described land set forth.

4. The arrangement of the purifying, decal1a burizing, and kneading chamber E, aside from and in relation to the direct-blast passageway D D, substantially as and for the purpose hereinbefore described and set forth.

5. The combination, with the hot-blast of an ore-reducing furnace, of a special heat-gen; erating furnace, C c', substantially as de= scribed, for the purpose of intensifying the heat of the blast sufficiently to enable the workmenthereby to melt either cast or malle= able iron when the same has at any time be;

come chilled or solidified in the said orerek duciug furnace, and thus avoid the great expenditure of time, labor, and money heretofore required in clearing; out such chilled or consolidated mass.

6. The combination, with si hotblast ore-reducing furnace, of a special blast-superbeming furnace, C c', in :L close channel, D, which communicates with the said ore-reducing furnace/and contains :i vessel, d', for refining by gravitation, substmit-ially as described, for the purpose of producing refined castiron ormalleable iron and steel direct from the ore in a' condition to be formed into ingots, and nztlly into bars, by the usual rolls or hammer during the same heut, as hereiubcfore set forth.

JOHN VV. BIDDLETN. Witnesses :i

, B ENJ. MoRrsoN,

W M.]H MoRIsoN. 

